The invention relates to a retaining segment for retaining a recoil plate of a hydrostatic piston machine.
In hydrostatic axial piston machines it is necessary to ensure, in particular during the intake stroke, that slide shoes, with which the pistons—mounted in a longitudinally displaceable manner—are supported on a running surface of a pivoting cradle, remain in contact with the running surface. For this purpose a recoil plate is used which engages around the slide shoes and thereby keeps them in contact with the running surface of the pivoting cradle. It is known to use retaining segments in order to fix the position of the recoil plate relative to the running surface of the pivoting cradle. These retaining segments also have a receiver for an actuating element and are fixedly connected to the pivoting cradle. In order to adjust the pivoting angle and therefore the stroke volume of the axial piston machines an adjustment device cooperates with the retaining segment via the receiver. The retaining segment, which is screwed to the pivoting cradle, therefore transfers the force produced by the adjustment device to the pivoting cradle and rotates it in a pivoting cradle bearing. Furthermore, it is known to provide a pressure feed-through in the retaining segment, via which pressure medium can be supplied for hydrostatic relief of the pivoting cradle. This pressure medium supply has a pressure medium input. This pressure medium supply is disposed on the retaining segment in such a way that it lies in the pivot axis of the pivoting cradle when the retaining segment is in the mounted condition. Pressure medium can therefore be supplied by means of a separate pressure supply rod in order to relieve the pivoting cradle.
In order to retain the recoil plate a retaining surface is formed on the retaining segment and extends along a portion of a circular arc. When the retaining segment is in the mounted condition this retaining surface lies on the recoil plate and therefore prevents the recoil plate from being lifted off.
In order to ensure emergency running properties of the axial piston machine the known retaining segments are produced from brass or bronze. The emergency running properties of brass or bronze are known. However, since brass or bronze is a relatively soft material the functionality of the retaining segment can be limited merely to the above-described functions such as the transfer of a low adjustment force and the retaining of the recoil plate. This means, however, that additional functions, such as for example coupling in of a high pressure displacement and a pivoting angle limitation, have to be provided at other points of the axial piston machine. This therefore ultimately leads to an enlargement of the construction size of the axial piston machine.